This invention generally relates to guidewires for use in vascular procedures such as angioplasty, angiography, and valvuloplasty, and more particularly to a telescoping guidewire and the methods of using the same in such procedures.
Guidewires are currently used to facilitate the placement of catheters in the arterial system of a patient for cardiovascular procedures such as coronary angioplasty, angioigraphy, and valvuloplasty. The guidewire is typically on the order of 20-50 cm longer than the catheter to permit the guidewire and the catheter to be advanced relative to each other as they are steered into position in the patient's body.
In order to change catheters, the guidewire is generally removed from the patient's vascular system an exchange wire is inserted in its place, the existing catheter is removed and a new catheter is steered over the exchange wire to its proper position, the exchange wire is removed, and the guidewire repositioned with the new catheter. The exchange wire is substantially longer than the guidewire, and it generally extends outside the patient's body for a distance greater than the length of the catheter. With a dilatation catheter having a length on the order of 120-140 cm, for example, a guidewire might have a length on the order of 175 cm, and an exchange wire might have a length on the order of 300 cm. The use of an exchange wire has the obvious disadvantage that it adds extra steps to the procedure. In addition, it requires the doctor to have an additional wire for this purpose.
What has been needed and heretofore unavailable is a system which eliminates the need for an exchange catheter without complicating the catheter exchange procedure. The present invention satisfies this need.